Thermal control of internal combustion engines



Feb; 13, 1940. L E, ENDSLEY 2,189,888

THERMAL CONTROL OF INTERNAL COMBUSTION ENGINES Filed Feb. '7, 1938 2Sheets-Sheet 1 a g 8 N L oouooooqioooo 0- x 1 l I 1\ II I i 111111!!! I!II IIIIIIIIIIIIII FIG. 1.

. INVENTOR LOUIS E. ENDSLEY ATTORNEY COMBUSTION ENGINES Feb. 13, 1940.E. ENDSLEY' THERMAL CONTROL OF INTERNAL Filed Feb. '7, 1938 2Sheets-Sheet 2 INVENTOR M LOUIS E. ENDSLEY 62M 4 new till Patented Feb.13,- 1940, 1

UNITED STATES THERMAL CONTROL OF INTERNAL COMBUSTION enemas Louis E.Endsley, Pittsburgh, Pa., Fairbanks, Morse & 00., Chicago,

ration of Illinois assignor to 111., a com Application February '7,'1938, Serial No. 189,110

20 Claims. This invention relates to thermal control of internalcombustion engines, and particularly to improved methods of and meansfor regulating the temperatures of lubricating oil and water utilizedinconnection with internal combustion engines employed for locomotivepropulsionr According to prevailing practice, particularly in connectionwith locomotives of so-called Diesel-electric type, the necessarycompactness of power plants due to space restrictions necessarilyimposed by permissible locomotive dimensions, operates to restrict theavailable area of cooling radiators for oil and water. Recent railroadexperience with equipment of the type noted in- I dicates that failurein engine operation has resulted by reason of these conditions, duedirectly to excessive oil and/or water temperatures. It is accordinglyamong the major objectives of the present invention, not only to provideheat exchange equipment of suflicient capacity to care for maximumattainable oil and water conditions, but to provide for a positiveautomatic optimum regulation of .the rates of cooling of either or boththe lubricating oil and water utilized with an internal combustionengine as a locomotive prime mover.

Specifically in connection with locomotive engine cooling, an entirelydifferent set of conditions prevails when the locomotive is in operationat speed, due to the greatly enhanced air-speed as compared with coolingconditions when the locomtive is at rest, and air circulation must beentirely mechanically provided for. For these reasons it will at onceappear to those skilled in the art that the problem is presently onewhich exists principally in locomotives propelled by internal combustionengines as distinguished from the problem prevailing in connection withengines of non-mobile type, although many of the improvements to bedescribed are applicable to stationary engines. It is accordingly anobject of the present invention to provide suitable agencies fordirecting air into cooling relation with a portion of a heatinterchanger assembly such as a radiator, in response to movement of thelocomotive, and also to provide improved means for assuring a definitenecessary minimum rate of air movement irrespective of motion ofthelocomotive.

Yet another object of the invention is attained in an improvedarrangement of air-directing and propelling agencies, which willfunction equally, or substantially so, in either direction of operationof the locomotive, i. e., forward or backward. The advantage of theseprovisions as an important objective of the invention is at onceappreciated, when it is considered that heretofore prevailing coolingequipment will function normally, only in one di ection of operation ofthe engine, being the usual normal forward movement.

More specifically, as reflected in the present design embodying theinvention, is the objective of providingan improved movable louvreassembly which operates preferably under full automatic thermostaticcontrol in response to oil temperatures and water temperatures in alocomotive of a type characterized by internal combustion enginepropulsion, such as Diesel-electric locomotives.

A further important and general object of the invention is attained inan automatic compensation of cooling effects on either or both oil andwater systems in a locomotive type internal combustion engine, to carefor differences otherwise resulting from the eifects of head winds, tailwinds, as well as lateral windage efiects on the locomotive, at the sametime caring for differences in cooling rate which would occur, but forpresent improvements, due to the reversal in direction of movement ofthe locomotive.

Somewhat ancillary to-the foregoing object, are certain objectiveimprovements in design of cooling system for an internal combustionengine of the type noted, whereby the system will operate effectively,in either direction of movement of the locomotive, and desirably underfull automatic regulation of either or both water and oil temperatures.

Still further objects of the invention may be stated as the improvementof provisions for limiting the temperature rise of either jacket wateror lubricating oil, or both thereof, including provisions, operativeupon attainment of predetermined limits, so as to vary, as throughengine governor loading, theengine power and hence the rate ofdissipation of waste heat by the engine.

Yet another important object of the invention is attained in improvedfacilities for proportioning a given supply of cooling air, betweenthose parts of the supply devoted respectively to the cooling of jacketwater and to the cooling of the lubricating oil, this object beingdesirably attained by an interrelated system of controls which more orless independently serve respectively to control jacket watertemperature and the temperature of the lubricating oil, the arrangementbeing further such that a variable supply of cooling air may yet be mostadvantageously proportioned between the noted cooling agenies.

Another object of the invention, akin to those heretofore stated, may benoted as the maintenance of water temperatures or'oil temperatures, orboth, within optimum ranges, practically irrespective of ambienttemperatures and windage conditions.

The foregoing and numerous other objects will appear as the descriptionproceeds, when considered in connection with the accompanying drawings,illustrating a presently preferred exemplary embodiment of theinvention. -In the drawings:

Fig..l is aplan view of an end portion of a locomotive unit with the topor roof structure broken away, and showing the preferred disposition ofthe locomotive engine with respect to the radiators and certain othertemperature regulat- Lng instrumentalities; Fig. 2 is a sectionalelevation taken at line 2--2 of Fig. 1; Fig. 3 is a transverse sectionalelevation taken at line 3-3 of Fig. 1; Fig. 4 is a plan view of thatportion of the locomotive unit illustrated in Fig. Land-showing,schematically, various temperature controlling elements and theirconnections such as may be utilized in practicing the invention, andFig. 5 shows a portion of a modified control system.

Making reference to the embodiment of the invention selected for presentdisclosure, it is contemplated that each locomotive, as utilized inservice, shall be comprised of a pair of functionallyindependentlocomotive units connected back to back; each such unit consisting, asto major items of equipment, of one or more internal combustion enginesof water-cooled type, say direct-connected to'an electric generator,provided with the usual 'exciter and control equipment. Propulsion isdirectly effected by driving motors carried by the driving trucks, theinstallationembodying electric control equipment which may be of one ofthe types .now known in the art and hence is not herein described indetail. The two units normally constituting the complete locomotive arepreferably articulately connected, depending on length of the coupledunits, roadbed conditions and other factors. It is to be understoodhowever, that the control features of the present invention areequallyapplicable to a single unit locomotive.

The cooling system is advantageously located, by reason of facility ofcooling air supply, near the end ofthe unit, although this location isnot absolutely necessary nor indispensable tothe operation of theapparatus to be described. As both of the units areor may be identical,the description will, for brevity, be confined to one thereof which maybe presently considered as the cooling assembly for the forwardlocomotive unit of the operatively related pair. 7

Referring now by numerals of reference toth drawings, the front endportion of thebody or housing of the locomotive proper, is indicatedgenerally at 20, and the end closure of the body shown at 2|, providedwith a louvred or grilled opening 22 for the entrance of cooling air.The louvres of the grille 22 maybe and bypreference are, manuallymovable-into positions of difierent angularity so as relatively toobstruct or close the front louvre opening, or to permit any selectedvolume of air up to the practical maximum, to enter the air space to bedescribed, within the locomotive. The right side wall 25 of thelocomotive body, is interrupted to provide an opening- 26, mounted justwithin which is a water radiator 21. This radiator is preferablydisposed vertically, or in any event, in a plane approximating that ofthe side wall 25 of the body. In corresponding position and for exampleof corresponding extent, is an oil radiator 28 carried by the side wall30 in similar relation to the mounting of the water radiator 21. It maybe noted that the water radiator is connected by supply and return.piping 3| (Fig. 4) to the usual cooling water Jacket of the enginedesignated generally at 32, and thus serves in known manner toreceivethe cooling water, sub- .iect same to the cooling effect of thestream of cooling air, and thence through the return piping, restore thewater to the jacket. The oil radiator 28 is by preference connected, notdirectly to the oil circulating system of the engine, but to a heatinterchanger 33, so that the radiator 28 serves indirectly to cool theoil through the agency of water circulation. The interechanger 33, notshown in detail, may consist for example of one of the well known typesof tube and header exchanger. The advantages of water cooling of the oilwill be appreciated by those skilled in the art, and although the unit28 is referred to as an oil radiator, it is nevertheless preferred to beutilized as a water radiator for ,the indirect cooling of theoil.

In Fig. 4, numeral 34 denotes piping connecting the so-called oilradiator 28 and interchanger 33, andjnumeral 35 denotes the oil linesinterconnecting the engine and interchanger 33.

. Extending within the nose or head end portion of the locomotive, is asubstantially air-tight cooling-air conduit, so formed as to constitutea chamber of substantial size, the opposite walls of this conduit beingindicated at 36, which walls may be continued to form top and bottomclosure portions 31. The chamberedconduit for the cooling air has itsclosure completed on the inner end by a partition structure which isshown as substantially V-shaped in horizontal'section, the V-shapedpartition structure being indicated at 38, and 39 representing the two1at-- eral arms or branches of the conduit resulting from the shape andlocation of the partition structure.

- Disposed alongside the water radiator, preferably but not necessarilyexternally. thereof, is an assembly of adjustable louvres, theindividual louvre forming elements 40 of which are each pivotedat itsinner edge or end, and the louvres of the group being connected forcorresponding opening and closing movement as through link elements I,each pivotally connected between adjacent pairs of louvres. For reasonswhich will hereinaftrmore clearly appear, it is preferred that thelouvres 40' be of a. quasistreamline horizontal section so as tominimize turbulence, eddies and cavitation effects of the air inpassing. through both the louvres and the radiator.- It will be obviousfrom the arrangement of the set of louvres 40 adjacent the waterradiator 21, that by closing the louvres, air circulation will besubstantially precluded through or adiacent the radiator. Thisadjustment is, according to the present -invention,

preferably fully automatic in nature, and is attained through the agencyof a bell crank control lever 42 and servo-motor 43, the actuatingelement 44 of which is pivotally connected to the bell crank lever 42.The details of structure and function of the servo-motor 43arehereinafter described in more detail in connection with thedescription of control features.

' e The streamline section of the movable louvre- 5 but to a lesserextent.

25 inafter more clearly appear.

the openings provided between the louvres 22 in advantage is realized inminimizing the resistance of these elements to the air. Some improvementis also noted on the front end of the locomotive by reason of thestreamline louvres, It has been determined that with identical unitsconnected back to back, some 25% more power is required for cooling airdisplacement in the rear unit, than in the forward unit, but that thisdifference can 10 be somewhat reduced by the streamline section of thelouvre-forming elements.

Similarly to the automatic water radiator louvres, is provided a set ofadjustable louvres for the oil radiator 28, the latter louvres being 15indicated at 45, and articulately connected through link elements 46 ina manner preferably similar to the linkage for the louvres 40. Theadjustment of the louvres between fullopen and full-closed positions iseffected 20 through a bell crank lever for example, 41, connected to theactuated element 48 forming a part of or associated with a servo-motor49. The device 49 is or may be identical with the servo-motor 43, andhence its structure will here- The oil radiator louvre elements 45 arepreferably, after the manner of the water radiator louvres, ofstreamline form, and are so formed for the same purpose.

There is desirably provided for the forced cir- 30 culation of airthrough the chamber of cooling air duct, in order to assure at all timesa dependable air circulation even though the locomotive be at rest, avariable displacement device for the cooling air. This consists,according to present pref- 35 erence but without any understoodrestriction as to type, of a propeller type fan or blower (see Fig. 4),the blower being actuated by a reversible motor 50, and the blowerassembly indicated generally at 5!. The fan itself is provided withblades 52, each mounted for a limited rotative movement about its ownlongitudinal axis, and associated with variable pitch mechanism 53.Mechanism for varying the pitch of propeller blades is well known in theart and a full de- 15 scription of a type thereof suitable for use inconnection with the present invention may be found in the monthlyperiodical Aero Digest, issue of July, 1938.

For the purpose of effecting automatically, the

so desired change in pitch of the blower or fan there is provided aservo-motor 54, which may be of a-type similar to the devices 43 and 49above described, and the detail of which will hereinafter more fullyappear.

A further agency for control of the stream of cooling air directed'intothe cooling air conduit,

consists of a swingably mounted air control fin or splitter 55, pivotedas at 56. The splitter fin is utilized for the purpose, as will latermore clearly m appear, of relatively obstructing the fiow of air to oneof the radiators, thus favoring the flow to the other, andv henceproportioning the supply of air between the pair thereof in the unit.This control is, by great preference, fully automatic in nature, and iseffected through an articulate link-.

age generally referred to at 51 and actuated by the control-actuatingmember 58 of a fin servomotor 59. The latter may be and is by preferenceof the same general type as the devices 43,

49 and 54 heretofore referred to.

From the preferred arrangement of the two 10- comotive unitsarticulately assembled to form the complete locomotive, it will appearobvious that as one of the units is moving in, a relatively forwarddirection, air will be received through the head end of the locomotive,and thence be displaced rearwardly into the chamber or conduit branches39, under the influence of the forward movement of the locomotive'aswell as under any displacement effect of the variable blower assembly5|. Assuming the air control fin 55 to be in a central or midposition,substantially half of the air will be diverted laterally toward and intothe' water radiator, the remaining half in an opposite direction andinto the oil radiator. After passing through the radiators, assuming thelouvres to be open, the air stream will find its exit laterally of andalong the locomotive body. It will be obvious that with both sets oflouvres in their fully closed position, substantially no cooling effectwill be exhibited on the two radiators. Such a condition will desirablyobtain during the starting period of the engine and during a preliminarywarming period. Following a preliminary temperature rise in the coolingwater and oil radiators, the effect of the control system hereinafterdescribed is such that the louvres will open to an extent usuallysuflicient to permit the passage of air through the radiators in suchvolume as to maintain temperatures therein, at the predetermined optimumaccording to thermostat setting, as will later appear. During this firststage of the control cycle, it will be assumed for convenience ofdescription, that the variable pitch propeller is operating at zeropitch, or, since it may be of fixed pitch type and operated by avariable speed motor for example, it will be assumed that there hasresulted no substantial displacement of air thereby. Assuming, however,

. tioning of temperatures of the two radiators, the

system will serve, through the fin servo-motor 59, to move the controlfin 55 from an initial position of rest, toward one of the radiators,for example, the water radiator 21, thus relatively restricting the airflow thereto, and relatively enhancing the air flow toward the oilradiator 28. However, should there still occur an undesirable furtherrisein temperature in one or either radiator, in spite of the wide openlouvres associated therewith, the pitch of the variable pitch propellerfan 5| is automatically augmented through the effect of servo-motor 54to increase the volume of cooling air to the radiators which willobviously have the effect of still further tending to offset the risingfluid temperature. Should this last change of control still not besufficient to restore the temperatures in both of the radiators to avalue within the predetermined limit, there is provided,.

as hereinafter more fully described, an automatic loading control of theengine, which in effect, serves as an automatic load-limitingarrangement operating to reduce the power of the engine, for example, asthrough the loading of its governor spring, to a safe figure such thatthe cooling system can care for the waste heat as fast as dissipatedinto oil, water or both, by the engine.

It is a preference that the capacities of the two radiators 21 and 28 besuch as to care for the full load 01% the engine at any reasonablyexpected maximum ambient air temperature, say '110 degrees F.

provision there would occur some interference with the air stream by theadjacent car of the train just rearwardly of the locomotive.

To the end of maintaining the propeller type fan in correct angularrelation to the air stream 1 moving inwardly or outwardly of the endporof the radiator, and because of the .agencies and their function,

tion of the cooling air conduit, it is a distinct preference to locatethe fan shaft at a substantial pitch or angle to the horizontal. Thegenera1 course of the air into and through the cooling conduit, variabledisplacement device, radiators, etc., has been heretofore referred to inreference to the forward direction of the locomotive. It will beunderstood however that in case the assembly of Fig. 1 is moved intherelatively reverse direction, as on the rear unit of the articulatedpair of units, the direction of air movement will be relatively thereverse of that described. Consequently, while in the front end of thecoupled units the louvres form air exit passages, in the rear such unitthey will serve as air pickup members, deflecting the air inwardlyrelative reversal of rotation of the displacement device ii, thedisplacement assembly will serve in the rear unit to discharge the airupwardly and outwardly through what was formerly discussed as the intakeportion of the cooling air conduit. It will nevertheless appear that thedisplacement of the blades of the variable pitch propeller, and thelateral control displacement of the fin or air splitter 55, will havethe same functions as heretofore described.

Proceeding now to a'description of control through which are attainedthe results above discussed, there has been selectedas an illustrativeembodiment, a

v temperature control system of combined electric and pneumatic type,and wherein somewhat separate, yet functionally interrelated controlorganizations, one for the jacket cooling water and another for thelubricating oil, are provided. The two control organizations may besubstantially identical with respect to the character and relationshipof their component parts, and accordingly an explanation of water jackettemperature control, will serve in substantial part, to cover bothcontrol organizations. The manner in which the water jacket and oiltemperature regulating means differ, will be pointed out as thedescription proceeds.

In Fig. 4, 60 designates a bi-metallic bar or thermostat element, shownas mounted in the conduit 3i which connects the water jacket outlet ofthe engine to the radiator 21, the element 60 being desirably locateddirectly in the path of the water as it leaves the engine, so that itstemperature will follow closely that of the water in the Jacket. Warpingmovement of element 60 in accordance with changes in water temperature,is transmitted by suitable means to the control unit indicated generallyat iii, of a reversible electric motor 62, such means being illustrateddiagrammatically as comprising a plunger 63 which extends from thethermostat element 60 outwardly through apacking gland inthe wail ofpipe 3| for connection with a switch lever 64, representing theactuating member of the motor control unit 6|. Such control unit mayconsist of what may be termed a double-pole, double throw reversingswitch, having a pair of contacts 65, insulated from each other andmounted on the extended arm of the switch lever 64, the contacts 65being connected to a supply of direct current provided by the mains 66.Suitably spaced at opposite sides of contacts 65, are the pairedcontactsli'l and 68 connected by leads 69 and 10, respectively, to motor62, in such manner that the motor will rotate in one direction whensupplied with current through contacts 61, and in the opposite directionwhen supplied with current through contacts 68. The motor field windingH is connected by suitable leads'to the mains 66.

Motor 62 is operatively connected, through a suitable reduction gearmechanism indicated generally at I2, to the control arm 13 of apneumatic, so-called self-lapping valve 14 which provides a means forregulating accurately the air pressure applied to the pneumaticservo-motors 43 and 54, previously referred to. Self-lapping valves arewell known, particularly in connection with their application to brakesystems for railway cars, such valves serving automatically to lapofithe flow of air when the pressure in the brake cylinder, or otherpneumatic actuating device controlled thereby, builds up to a pressurecorresponding to the particular position of the valve lever arm. Iflower pressure is desired the valve arm is moved, for example, to theleft (Fig. 4); if greater, to the right-the cylinder pressureimmediately falling or rising an amount corresponding to lever movement.A detailed description of a self-lapping valve assembly suitable for usein the control system of the present invention, may be found in bulletinNo. 2455 of April 1932, published by Westinghouse Traction Brake Co. ofPittsburgh, Pa.

The gear reduction mechanism 12 may include a driven rack bar 15mechanically coupled to lever arm 13 of the self-lapping valve, a pairof limit switches 16 and 11 being arranged with respect to the lever arm13 and disposed in the motor circuits 69 and I0 so that movement oflever 13 to either of its extreme positions opens one of the limitswitches. It will appear that when one of the limit switches is'opened,as aforesaid, motor 62 will stop and can be reenergized to rotate onlyin a relatively reversed direction. It is desirable to provide for aslow movement of the valve lever 13 and the reduction gear assembly 12should be ned so that the lever arm travels from its zero pressure pointto its maximum pressure position in not less than one minute.

The self-lapping valve is connected, as by conduit -18, to a suitablereservoir. 19 providing a supply of air under pressure, and controls thepressure of the air in the pipe 80 leading to the cylinders ofservo-motors l3 and 54 through self-lapping valve 14 and the louvrecontrol servo-motor 43, is such that the water radiator louvres arefully closed when lever 13 is in one extreme position, and fully openwhen lever 13 is, for example, mid-way between its extreme positions,each increment or decrement of lever movement producing achange ofcorresponding degree in the positions of the louvre fins 40.

The self-lapping valve 14 serves, additionally, to regulate thedisplacement capacity of the fan 5| which is adapted to augment the flowof air through the water and oil radiators when such becomes necessaryin order to reduce abnormal engine temperatures, the fan becomingeffective for this purpose only when the water radiator louvres are infull-open position. Thus valve 14 may be adapted, for example, to eifecta gradual pressure variation in line 80 through a range of from to 60pounds per square inch gauge pressure. Now, the spring associated withservo-m0- tor 43 may be so designed and loaded to permit of fulldisplacement of the servo-motorpiston when 30 pounds of air pressure isapplied thereto, such full displacement position corresponding to fullopen position of the louvres 40, and to a midway position of the valvelever 13. When air pressure in line 80 is increased beyond 30 pounds persquare inch, as by movement of valve lever 13 beyond its midwayposition, servo-motor 54 becomes effective to increase the displacementcapacity of fan assembly The impeller or fan assembly 5! is driven bythe electric motor 50 which may be of variable speed type, the motorspeed being controlled by a suitable variable resistance unit actuableby the servo-motor 54. However, I prefer to employ an impeller ofconstant speed type wherein changes in displacement capacity areeffected by altering the pitch of the impeller blades. Devices of thischaracter are well known and a detailed description of the same isbelieved unnecessary. In Fig. 4, an operative connection betweenservo-motor 54 and the pitch changing mechanism (not shown) of impeller5| is indicated as provided by a direct connection to the piston, theservo-motor 54 being adapted by virtue of its spring loading, to

vary the propeller blades from zero to maximum pitch when subjected tocontrol pressures within a range of from 30 to, say; 60 pounds persquare inch.

The foregoing description sets forth means, which function in a mannerto be hereinafter explained, for controlling and maintaining thetemperature of the engine jacket water within predetermined limits whenthe engine is running. A series of instrumentalities similar to thosepreviously described is provided for controlling the temperature of theengine lubricating oil. Thus, a second thermostat 83, which maycorrespond to thermostat 60, is located in the oil line or piping 35,preferably at a point where the oil leaves the engine, the thermostat 83having a reversing switch 84 associated therewith which controls theenergization and direction of rotation of a reversible motor 85 which,in turn, actuates the control lever of a self-lapping valve 86. Such'valve is connected as by branch pipe 81 to a servo-motor 49, serving toregulate the air pressure thereto for adjusting the positions of louvrevanes 45 associated with the oil-cooling radiator 28. The servo-motor59, heretofore described, is

operable in a somewhathigher pressure range than the unit '49, and is incommunication with the self-lapping valve 85 through branch pipe 88,

and is connected to the lever mechanism 5'! which actuates thedeflecting fin 55. It will thus appear that the water radiator louvres40 and the air impeller 5| are under the control of thermostat 60 whichis thermally responsive to the jacket cooling water, and the oilradiator louvres 45 and the deflecting fin 55 are under the control ofthermostat 83 responsive to temperatures of the lubricating oil.

Let it be assumed that the described means are applied to a locomotivepowered by an internal combustion engine which operates with maximumefficiency when its jacket temperature is maintained between the limitsof 170 degrees and 180 degrees F. Under such condition the waterthermostat and its attendant switch would be designed so as to startmotor 62 in one direction when the water temperature reached 177degrees, and to start the motor in the reverse direction when the watertemperature drops to. 173 degrees, the motor being idle for intermediatetemperatures. The switch contacts 61 and 68 are thus arranged incontemplation of a possible over-run of approximately 3 degrees, beforethe means which control the flow of air through the water radiatorbecome effective.

When the jacket temperature falls to or below.

173 degrees F. the self-lapping valve 14 reduces the air pressure toservomotors 43 and 54 toward zero effective value, approaching the fullyclosed condition of louvres 40 associated with the water radiator andtending to reduce the pitch setting of the fan blades 52, so thatrelatively less cooling air is displaced thereby. When the jackettemperature rises to 177 degrees the contacts 65 of the thermostatswitch engage the contacts 68,

which it may be mentioned, are preferably spring-mounted for theprincipal urposes of providing for their yieldable engagement, and alsofor purposes of adjustment. The engagement of contacts 65 energizesmotor 62 which causes lever I3 slowly to increase the air pressure inthe servomotors 43 and 54. As the air pressure increases, the waterradiator louvres open correspondingly so as to permit more cooling airto pass through the radiator to reduce the jacket temperature. If thejacket temperature is not thus lowered after the louvres attainwide-open condition, corresponding to 30 pounds or more pressure in theservomotor 43, the self-lapping valve continues to increase the pressurein lines 80, 8| and 82. Servomotor 54 becomes eiiective when the linepressure exceeds 30 pounds, to increase the fan output, the fanattaining its maximum displacement capacity when a pressure of 60 poundsper square inch in line 82 is reached.

Under all except very extreme conditions, the increased flow of coolingair throughthe water radiator resulting from the open louvres, theaugmented air flow due to the fan, or both, will reduce the jackettemperature and cause the thermostat to interrupt the motor circuitbefore the jacket temperature exceeds 180 degrees F. Now, if the jackettemperature drops to or below 173 degrees F., the motor will bereenergized in the reverse direction, resulting, first, in a gradualreduction of air displacement by fan assembly 5 I, and thereafter, ifnecessary, gradual closing of the water radiator 40.

The maintenance of the oil temperature between predetermined llmits isaccomplished in a similar manner, the oil radiator louvres beingadjusted to pass more -or less air as dictated by the oil thermostat 83.However, with the controls con nected as shown by Fig. 4, no directoperative relathan the water radiator.

tion exists between the oil thermostat and the tan. If the oiltemperature is not reduced after the oil radiator louvres have beenmoved to full open position, displacement of the fin 55 to direct agreater portion of the cooling air through the oil radiator is effected.Such fin adjustment obviously will tend to reduce the amount of coolingair passing through the water radiator which, if necessary, will resultin increasing the fan output as previously explained; there is thusprovided a distinct functional interrelation between oil temperature andvolume of cooling air directed toward and through the oil radiator.

When the temperature of the atmosphere is degrees, which may be regardedas a, practical maximum, the several radiators require substantiallyequal amounts oi cooling air to maintain the oil and water at theirdesired temperature levels, which are approximately degrees F. for theoil and 1'75 degrees F. for the water. However, as the atmospherictemperature drops, the oil radiator requires decreasingly less coolingair Moreover, a side wind will tend to increase air flow through one ofthe radiators and decrease the flow of air through the radiator at theopposite side of the locomotive. Thefin 55 operates to compensate forthese varying conditions, coacting with other described means forcontrolling the flow of cooling air, and hence serves to maintain inpredetermined ranges, the oil and water temperatures.

If desired, the deflecting fin may be dispensed with and control ofcooling air eifected solely through the agency of the radiator louvresand the fan. In a system thusly modified, the previously describedmethod of louvre control may be employed. However, instead of providingtwo so-called secondary servo-motors (54 and 58) which begin to functionafter the oil and water louvres are moved to full open position, asingle secondary servo-motor, common to both oil and water temperaturecontrolling organizations, is operatively connected to the fan mechanismso that air displacement by the fan will be regulated in accordance withthe demands of either of the radiators. In the modified arrangement thefan output should be determined by the particular cooling system, oil orwater, having the greatest demand for augmented air flow.

This result may be accomplished in the manner illustrated schematicallyin Fig. 5, showing a constant speed motor 580 which drives a fan 52a ofvariable pitch propeller type, the mechanism (not shown) 'for varyingtheblade pitch being actuated by an axially movable shaft connected to thepiston of a pneumatic servo-motor 88. The servo-motor 88 may be of thegeneral type heretofore described, and wherein air pressure in excess of30 pounds per square inch in its cylinder, initiates movement of thepiston, such movement being opposed by a spring.

The air pipe 8!! leading to a servo-motor 88 is adapted to communicateselectively with either of the air pipes 82a and 88a through a valvestructure 8|,hereinafter described. It will be understood that pipes 82aand 88a of the modified system constitute branches leading fromselflapping valves 14 and 86, respectively, replacing pipes 82 and 88 ofthe system originally describedand illustrated in Fig. 4.

The valve structure 8| includes a freely movable piston 82 whichoperates under a pressure differential in lines 82a and 88a to place theone having the greatest pressure in direct communication withservo-motor 88, and serving simulnor 86, and serves,

taneously to close of! communication between the other line and the saidservo-motor. By means of valve structure 8| the control of fan output isunder the domination of the particular air line 82a or 88a carrying thegreatest pressure, and hence is influenced by the system, oil or water,having the greatest demand for augmented flow of cooling air. It will beobvious that the purpose of valve 8| is to enable servo-motor 88 to beeffected by the pressures in either of the lines 820. or 88a, yet toprevent undesired equalization of the pressures in these lines.

In the modified system, the louvres associated with'the oil and waterradiators will open to an extent depending upon the air pressure intheir respective servo-motors, such air pressures bein regulated by theself-lapping valves which, in turn, are controlled by thermostats in theoil and water lines of the engine. If, for example, the

temperature of the jacket water is not reduced 20 after the waterradiator louvres have attained full open condition, the control airpressure in line am will rise sufficiently to actuate the fanservo-motor 88, causing the fan to increase the flow of cooling air. Thecontrol arrangement prevails on the oil side of the combined system.Excessive temperatures in either the water jacket, lubricating oil, orboth, will result in increasing the fan output. If the same louvre andfan 25 fan power or amount of cooling air passing 30 through one of theradiators is sufficient to. reduce the temperature of its associatedsystem but the demand for augmented air flow continues in the othersystem, the fan will continue to displace air in accordance with thedemands of the latter system. However, the amount of cooling air flowing'through' the radiator of the first system,

whose temperature has been reduced, will be curtailed by the radiatorlouvres of that system.

In addition to the means heretofore described for maintaining the enginetemperature within predetermined limits, it is deemed advisable toprovide means which function to reduce the power of the'engine, andhence its heat output, should the radiators be inadequate, due toextremely high atmospheric temperatures or excessive engine loading orboth, or failure of one or more of the described control elements. Thusthe thermostat switches BI and 84 are preferably equipped with auxiliarycontacts 82- and 83, respectively, as shown in Fig. 4, which;communicate through suitable means with the governor or other directcontrol mechanism of the locomotive engine and function to eifect'areduction in engine power should the jaclgetwater and/or oiltemperatures reach dangerous values. Thus. the auxiliary contacts 82 arearranged to close an electric circuit which effects energization of anelectromagnetic control device 94, when the water temperature rises tosay 200 degrees F. The control unit 84 is shown operatively connected toa control arm 85 of the engine goverwhen energized, to move the governorcontrol arm 85 to a position corresponding to reduced engine power. Theoil thermostat is likewise through contacts 83 and associatedconductors, arranged to reduce the engine power, through the governor85, should the oil temperature rise to say degrees F., or higher.

The electromagnetic control device 84 may consist of any of severalknown types of electric motor and reduction gear assemblies, operativelyconnected to the governor control arm 85; however, as shown forsimplicity, the electromagnetic control unit may consist of a solenoidoperatively connected to a slotted end of the lever 95, the armature rodor shaft 91 being extended'for connection to a dash pot 98. Theprovision of a dash pot, or some equivalent motion-delaying expedient,is preferred, since it is desirable in the event maximum safetemperatures are reached in one or either of the OH and water radiators,to effect a gradual reduction of engine governor loading, or otherwiseto attain a gradual reduction in engine power output. It may also bedesirable in certain installations, to effect a gradual restoration ofthe engine control to its setting prevailing prior to the energizationof the unit 94. A convenient expedient through which may be attained adelayed complete actuation of the lever 95 in one or both directions, isshown in connection with dash pot 98. If it be supposed for example,that the dash pot consists of a double end fluid-containing cylinder,the ends of the cylinder on opposite sides of the piston may be put incommunication as through a small interconnecting conduit 99, the rate ofpassage of oil or other fiuid through which may be regulated as by valveI00. It will readily appear from the foregoing description that thearrangement is usually such that actuation of lever 95 in a direction toreduce engine power, is effected by energization of the unit 94, and theopposite or restoring movement effected through spring "II, which mayconsist either of the main governor spring,'or of a separate compressionspring for actuation of the lever 95 toward an inoperative orineffective position.

The foregoing description of the physical arrangement of cooling aircontrol and reaction elements, as'well as the description of the controloperating system, have included, for completeness, provisions forvarying the effective cooling air fiow through both the oil and waterradiators, the agencies for directing a greater or less proportion ofthe input cooling air, toward either of the paired'radiators, as well asthevariable displacement device such as the blower assembly 5| and itsautomatic regulating expedients, whereby is attained a complete controlof air flow through the cooling conduit. It is nevertheless, in spite ofthe complete control facilities described,.within the scope and purviewof the invention, to utilize separately, or in any subcombination orgrouping, any of the individual control agencies herein described. Forexample, it is understood as constituting a distinct advance in the art,to employ of itself, the improved con trol arrangement, for eitherradiator alone, provided by the movable louvres 40 or 45. Even thoughsuch louvres be fixed and not susceptible of control, manual orautomatic, it would nevertheless be within the scope of the invention toutilize for example, the cooling air proportioning arrangementexemplified currently by the air splitter fin 55 and associated parts;In the same manner, the variable air displacement device, exemplified bythe assembly Si, is susceptible of advantageous use of itself,particularly when subject to thermostatic control by theelectropneumatic arrangement disclosed, or some analogous regulatingagency.

Apart from the advantages to be attained by utilizing thesubcombinations or individual control provisions, the physicalarrangement of airdirecting elements is believed to be the mostadvantageous yet presented to the art, of locomotive engine cooling, andto exhibit many advantages, irrespective of whether, for example, theeifective volume of air through the radiators r trolled.

For a better understanding of operation of the control system presentlydisclosed by way of example, reference has been made to specificpressure ranges in the fluid-pressure portion of the control system;similarly, by way of illustration, optimum orders of oil and watertempera tures have been referred to as illustrative of usual bestoperating conditions, and as illustrative of ordinarily considered safemaxima of temperatures. It is however to be understood that the valuesherein given are merely illustrative and not to be regarded in anymanner as restrictive of temperature or pressure values or ranges.

A study of the foregoing disclosure will reveal that the invention inits broader aspects embraces a substant-iallycomplete system foreffecting full automatic thermal control of locomotive engine jacketwater and lubricating oil temperatures, and that, allparts of thecontrol system being in substantial measure functionally interrelated,this full automatic control is effective and fully compensatory for allvariable cooling factors, e. g.,

varying direction and velocity of wind, of itself or as influenced bymotion of the locomotive. It will further appear that this is trueirrespective of whether the unit, for example as shown by Fig. 4, ismoving in a relatively forward or reverse direction, and irrespective ofwhether, by reason of the influence of the automatic adjustable louvres,the splitter fin assembly 55 and variable displacement device the windis of either high or negligible velocity, directly abeam on either sideof the locomotive, or so to speak, directly ahead or directly astern. Itwill further appear thatthe control system and physical arrangementofparts as described, fully attains each of the objectives hereinabovespecifically set forth, as well as other advantages and contributions tothe art appearing in the description of parts and their operation.

Although the invention has been described by making a specific referenceto a presently preferred arrangement and combination of controlfeatures, many of such agencies may be varied, as may the location andarrangement of many of the parts described in detail; accordingly thedescription is to be understood solely in an illustrative and not in alimiting sense, and within the full intended scope and meaning of theclaims hereunt appended.

I claim:

l. The described method of thermal control of an internal combustionengine of a type provided with water-cooling and oil-cooling equipmentincluding radiators respectively arranged for the cooling of water andoil, which consists in circulating cooling air in a defined passage intocooling relation to said radiators, separately controlling the effectiveareas of portions of said passage directed to said radiators, inresponse to temperature variations of liquid in the said radiators, andfurther varying the displacement of air into said passage in response toa predetermined temperaor said radiators, upon attaining therein of apredetermined temperature with the associated air passage relativelyunobstructed.

3. The method of efiecting thermal control or water and oil temperaturesin an internal combustion engine, which consists in cooling the enginecylinders and cooling the lubricating oil through the circulation ofcooling liquids in spaced radiators, supplying cooling air from a commonsource and directing such air through a common conduit, thenceseparately into cooling relation to the respective radiators, and inproportioning the air delivered from the common conduit, to theindividual radiators, substantially in accordance with thermalrequirements of the respective radiators.

4. The method of efiecting thermal control. of water and oiltemperatures in an internal combustion engine, which consists in coolingthe engine cylinders and cooling the lubricating oil through thecirculation of cooling liquids in spaced radiators, supplying coolingair from a common source and directing such air through a commonconduit, thence separately into cooling relation to the respectiveradiators, and in proportioning the air delivered from the commonconduit, to the individual radiators, substantially in accordance withthermal requirements 01' the respective radiators, and in increasing thedisplacement of air in the common passage or conduit, in response topredetermined temperature conditions in the fluid in, or in thermalcommunication with either of said radiators.

5. The herein described method of effecting a thermal control of aninternal combustion engine provided with a water-cooling system and anoilcooling system, each including a radiator, which consists indisplacing air through a branched conduit, thence into cooling relationwith the respective radiators; proportioning the efl'ective flow of airin cooling relation to the respective radiators by control of theefiective sectional area of the branches of the conduit; furtherproportioning the air by varying the-delivery of air into the respectivebranches of the conduit all in response to thermal variations in therespective liquids to be cooled by the radiators, and further varyingthe displacement of cooling air in response to predetermined temperaturevariations of a relatively higher order, in one of said cooling systems.

6. The herein described method 01 eflectin thermal control of aninternal combustion engine of water-cooled type and provided with awater cooling radiator, which consists in supplying cooling air to theradiator, through a defined air channel controlling the cooling aireflectively delivered to the radiator by-variation of the outlet area ofthe channel, ;In response to water temperature; varying, thedisplacement of air in said channel in response to water temperaturevariations of a diflerent order, and varying the loading of the enginein response to predetermined temperature .variations of an orderexceeding that aforesaid.

7. In a cooling system for internal combustion engines of locomotivetype, a pair of radiators arranged opposite each other and laterally ofthe locomotive, adapted respectively to cool the engine jacket water andthe lubricating oil, an enclosing structure forming an air chamberbetween the radiators and provided with an air opening at one end, theside walls of the chamber being completed by a plurality of adjustablelouvres adapted to be regulated to vary the extent or area of airopening at each side oi the chamber and through the radiators, andthermostatic control means operable responsively to variations intemperature of the liquid circulating in the radiators to vary theextent of opening of the louvres. v

8. In a cooling system for internal combustion engines of locomotivetype, a pair of radiators disposed at opposite sides of the.locomotive,adapted respectively to cool the engine jacket water and the enginelubricating oil, an enclosing structure forming an air chamber betweenthe radiators and provided with an air opening at one-end of thelocomotive, a partition member in said chamber for directing air fromsaid opening laterally toward said radiators, a plurality of adjustablelouvres adapted to be regulated, and so located as to provide a variablearea of air opening adjacent each radiator, a blower and drive assemblylocated near the first said air opening, and being of variabledisplacement type, and thermostatic means operable responsively tovariations in temperature of the liquid circulating in at least one ofthe radiators, to vary the displacement of air by said blower.

9. In a cooling system for an internal combustion engine of locomotivetype, a conduit for direction of cooling air, arranged longitudinally ofthe locomotive and near one end thereof, radiators disposed at oppositesides of the locomotive and laterally of the conduit, said radiatorsbeing adapted respectively to cool the engine jacket water and thelubricating oil, the conduit being provided with an opening at one endof the locomotive, and an adjustable partition structure disposed withinthe conduit and serving to direct and proportion the air .therein towardand to the radiators.

10. In a cooling system for an internal combustion engine of locomotivetype, a conduit for direction of cooling air, arranged longitudinally ofthe locomotive and near one end thereof, radiators disposed at oppositesides of the locomotive and laterally of the conduit, adaptedrespectively to cool the engine jacket water and the lubricating oil,the conduit being provided with an opening near one end of thelocomotive, an adjustable partition structure associated with theconduit and serving to direct and proportion the air therein toward andto the radiators, and a set of movable vanes adjacent each of saidradiators, arranged, when closed, to complete the closure of the sidesof the chambered conduit.

11. In a cooling system for an internal combustion engine of locomotivetype, a conduit for direction of cooling air, arranged longitudinally ofthe locomotive and near one end thereof. radiators disposed,at oppositesides of the locomotive and laterally of Hie conduit, in fluid coolingcommunication respectively with the engine jacket water and the enginelubricating oil, the conduit being provided with an opening near oneend' of the locomotive, a partition structure associated with theconduit and serving to direct the air therein toward and into theradiators, a set of movable vanes adjacent each of said radiators,arranged, when closed, to complete the closure of the conduit about theradiators, and means for independently regulating each set of saidvanes, associated with the respective radiators, each in accordance withand responsive to the temperature of liquid circulated within theassociated radiator.

12. In a cooling system for an internal combustion engine of locomotivetype, a conduit for direction of cooling air, arranged longitudinally ofthe locomotive and near. one end thereof, radiators disposed at oppositesides 01' the locomotive and in the path oi. cooling air circulated inthe conduit, said radiators being adapted respectively to cool theengine Jacket water and the lubricating oil, the conduit being providedwith an opening near one end of the locomotive, a partition structureassociated with the conduit and serving under certain conditions to adirect the air therein toward and into the radiators, a set of movablevanes adjacent each oi said radiators, arranged, when closed, to com-Plete the closure of the conduit about the radiators, means forindependently regulating each set of said vanes, associated with therespective radiators, each in accordance with and responsive to thetemperature of liquid circulated within the associated radiator, a fanor blower assembly within the conduit, and means operable responsivelyto temperature oi the engine Jacket water, for varying the displacementof air in the conduit by said blower assembly.

13. In a cooling system for an internal combustion engine of locomotivetype, a cooling air conduit forming a chamber near one end of thelocomotive, radiators arranged in liquid-cooling relation to the engineand disposed at opposite sides of the chamber and laterally oi thelocomotive, said conduit having an air opening at the end of thelocomotive and extending in a general direction longitudinally oi thelocomotive, a movable vane element disposed internally of the conduit,and means operable in response to the temperature of liquid to be cooledby one of the radiators, for varying the position of said vane elementin a direction from either radiator and toward the other, whereby toproportion the volume of air delivered to the respective radiators.

14. In-a cooling assembly for an internal combustion engine oflocomotive type, a pair of oppositely disposed radiators, a conduit forcooling air, having its intake atone end of the locomotive and adapted,in one direction of operation of the locomotive, to discharge throughthe radiators, and a vane element movably mounted in said conduit so asto be-swung from either radiator and toward the other, whereby toproportion the air tram the conduit, directed to the respective radiars.

15. In a cooling system for an internal combustion engine and incombination with a locomotive adapted for propulsion by the engine, theengine being oi a type requiring liquid cooling, a pair of radiatorsmounted laterally or and near one end of the locomotive, a chamberedconduit structure having an opening adapted for air intake, andextending therefrom near one end of .the locomotive an thence betweenthe radiators,

and a substanti v-shaped structure at the opposite end of the chamberedconduit, and serving to deflectthe air i'rom said end of the chamberedconduigflaterally into the radiators.

16. In a cooling system ror an internal combustion engine and incombination with a locomotive adapted for propulsion by the engine, theengine being of a type requiring liquid cooling, a pair of radiatorsmounted laterally or and near one end of the engine, a conduit structureextending from an inlet portion near one end of the locomotive andthencebetween the radiatomandalub stantislly v-shapedstructureattheoppositeendof the conduit, and serving to deflect the air from the intake portionof the conduit, laterally into the radiators, independent meansincluding movable vane elements controlling the passage of air throughthe respective radiators, and thermostatic control means independentlyoperably associated with said vane elements, for efiecting controlthereof responsively to changes in temperature of liquids to becirculated in the respective radiators.

1'1. In combination in a cooling system for an internal combustionengine arranged for locomotive propulsion, and a locomotive driventhereby, a radiator constituting an element of a liquidcooling system ofthe engine, a cooling air conduit directed toward said radiator, a tanor blower arranged to supply air to said conduit, the loco motive beingprovided with an air intake passage having an inlet opening in the upperportion of one of its end walls, said passage extending inwardly anddownwardly of the locomotive body structure, for communication with saidconduit .and for supply of air to said blower.

18. In combination in a locomotive including an internal combustionengine .for propulsion thereof, a cooling system for the engineincluding a radiator, arranged along a side wall of the locomotive, anair inlet opening in the upper portion of an end wall of the locomotive,an air conduit extending from said opening inwardly and downwardly oithe locomotive body and terminating at said radiator, and a fan disposedin said conduit adjacent said opening, said fan being inclined toconform with the inclination oi the inlet portion of said conduit andadapted for the induction of air inwardly and downwardly o! the end oi.the locomotive body.

19. In a thermal control assembly for the cooling system of an internalcombustion engine of locomotive type, and in combination with a loco-.motive propelled by the engine, a radiator in cooling association with'acirculating liquid from the engine, an assembly of adjustable louvresassociated with the radiator, and arranged to control the eilective e ofair therethrough, thermostatic control means for said louvres, operablein response to a predetermined temperature of said liquid, and anengine-load control device operable in conjunction with saidthermostatic control means, but responsively to liquid temperatures 01'a higher order than those normally influencing the louvre-controllingeflects oi said thermostatic means.

20. In a thermal control assembly for the cooling system of an internalcombustion engine of locomotive type and in combination with alocomotive propelled by the engine, a radiator in cooling associationwith a circulating liquid from the engine, an assembly of adjustablelouvres assonouns I. mostly.

